Versioning assets separately by sticking them in new subfolders is just re-inventing ETags in a bad way. Just use ETags.

The point of the folder versioning scheme the article proposes is to make rollbacks easier. You can easily rollback a /assets/v2 folder to /assets/v1 by updating your server template, but if you have a dozen separate version folders (with different latest version numbers) for each resource then it's no longer easy to roll those all back.